Palm Treo650

If you'd been watching the H&D SVN repository you might have noticed several commits mentioning 'palmt680', and indeed we have a new project. I'd like to welcome our newest developer, Satadru who has started working on the port.

On a related note I've discovered how to talk to the GSM phone module (it will probably also work with the CDMA one) on the 650. After a little poking around, I discovered my initial assumptions about the BP (baseband processor - the 'smart' part of the phone module) being hooked to the ASIC UART were wrong. The BP is actually on the FFUART, so to talk to it all you need to do is open /dev/ttyS0 at 460800 8N1 with RTS/CTS flow control. It seems that Palm OS puts it into a binary protocol mode, so it'll just spit gibberish at you. After a bit of tinkering around with ASIC though, I noticed one of registers changing if the phone was on or off. Toggling this register appears to reset the module and you can speak to it in plain ASCII again.

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I realise I ended up going a bit quiet on the LD project. I'll try to document our progress a bit better with this one. So check the project blog from time to time.

Read on for some (non-exhaustive) notes on what needs to be done for Treo 650 Linux.

I have just committed some initial Treo 650 code to SVN. Booting is accomplished using Cocoboot, for now you need compile Cocoboot with James McKenzie's patches enables using the -DTREO650 flag to work around read-only memory map problems.

Things that work:

• LCD framebuffer console
• Booting off an ext2 partition on an MMC/SD card
• Controlling LCD backlight brightness via /sys
• Built-in QWERTY keyboard

Here's some binaries for those who know how to partition memory cards and use the console.

Those of you into PDA phones will be interested to know the Treo 650 project has basically been taken over by James McKenzie. There's a few pictures on his website. As you might guess from the pictures he - as a much more capable ARM developer than I - has been cleaning up and enhancing Cocoboot. While there isn't much there just yet, I you should definately bookmark his Treo Linux page.

Please go here to see pictures of Treo 650 with GPE inside. May the Force be with you, Luke

Matthew has wrote big article covering different ROM issues. He also described boot process. Believe or not, but Treo has a very long bootloader chain which consists of 3 (three !) loaders. Read here.